What can cause Failed to Fetch red screen loading project error?

I always make few backups a day because i never know when i receive this error again. Recently i receive this red screen when i save my project, of course progress is lost but i always have (20min before saved) backup.

Now i try open my project with from yester day and from week ago, 1 month ago, 2 months ago and all files cause red screen

So i think files are ok, why construct cant open with succes?

Prabably i forget something or maybe setting of system are wrong?

PS

When 3D shapes are added to construct im back to making games Thank You Ashley!

Construct should never crash, even if you open an invalid project, or if network requests fail. If you run in to any such problem please file an issue following all the guidelines. You can also check the browser console (usually opened by pressing F12) for any more error details.